A typical packaging bag for packaging various articles such as foods, pharmaceutical and medical products and groceries is sealed at an upper side thereof. When the packaging bag is opened, films forming a bag body are torn apart from notches and the like (as a starting point) provided on both sides of the packaging bag.
However, it is difficult to linearly cut the films forming the bag body. Accordingly, a structure to be opened at a predetermined position has been desired.
There has been proposed a packaging bag provided with a reinforcement string as a guide and a guiding tape, in which the guiding tape is guided by the reinforcement string to be linearly torn away, whereby the packaging bag is opened (for instance, Patent Document 1).
Alternatively, there has been proposed a technique to open a packaging bag by linearly tearing away a film using a cutting string (for instance, Patent Document 2).
[Patent Document] 1 JP-A-10-59384
[Patent Document] 2 JP-A-6-286758